Danny Meyer, CEO of Union Square Hospitality Group, and Shake Shack CEO Randy Garutti were fresh off a plane from Istanbul, Turkey, where the duo recently opened its first Shake Shack location in the country, located in the Istinye Park Mall. “It was the busiest opening day in the history of Shake Shack,” Garutti told The Daily Meal, while being honored at The 2013 Whole Foods Market New Taste of the Upper West Side.

A second Shake Shack location in Istanbul is slated to open within the month, he explained. Shake Shack uses local Turkish beef to create its classic menu that is the same in all of their locations around the world. However, the Turkish Shake Shack outposts will also include items like macaroons and baklava. “We always try to add some local flavor,” remarked Garutti.

Washington, D.C. is up next, scheduled to open in the next three weeks and London will follow in early July.

Both Meyer and Garutti remarked that the Upper West Side of Manhattan holds a special place in their heart in terms of how the Shake Shack brand began to be a global phenomenon. It was the second location the duo opened after its flagship in Madison Square Park. When the Upper West Side’s shop became such a success, they decided it was time to seriously build out the brand, said Garutti.

Meyer explained another reason for the brand’s success is simply how it brings people together. “Food and hospitality are the two most universal languages that bond all human beings. It’s how I know how to talk to people,” he said, noting that expanding Shake Shack has also been his ticket to learning about different parts of the world.

When asked what his favorite Shake Shack menu item was, Meyer said simply, “a single cheeseburger with a slice of onion on it.”